Indicator for running deconvolution

[czackl]

There should be an indicator showing the user a deconvolution is running.

Either with a "Waiter" or withProgress()
https://github.com/JohnCoene/waiter
https://shiny.rstudio.com/articles/progress.html

[alex-d13]

This is working, but we might want to increase the size of the progress bar :)